Related papers: Higher Twist Effects in Polarized DIS
We have studied the deep inelastic scattering (DIS) of polarized charged leptons from polarized nucleon targets and evaluated the polarized nucleon structure functions $g_{1N,2N}(x,Q^2)$ as well as the nucleon asymmetries $A_{1N,2N}(x,Q^2)$…
We examine the influence of the recent CLAS and COMPASS experiments on our understanding of higher twist (HT) effects and the gluon polarization, and show how EIC could discriminate between negative and positive gluon polarizations. We…
The impact of positivity constraints on the polarized parton densities has been studied. Special attention has been paid to the role of positivity constraints in determining the polarized strange quark and gluon densities, which are not…
Recent precision spin structure data from Jefferson Lab have significantly advanced our knowledge of nucleon structure in the valence quark (high-$x$) region and improved our understanding of higher-twist effects, spin sum rules and…
Higher twist effects in the deeply inelastic scattering are studied. We start with a short review of the theoretical results on higher twists in QCD. Within the saturation model we perform a twist analysis of the nucleon structure functions…
The experiment E155 at SLAC measured the spin structure functions g_1 and g_2 of the proton and deuteron. The experiment used deep inelastic scattering of 48.3 GeV longitudinally polarized electrons incident on polarized solid ^{15}NH_3 and…
We re-examine the estimates of the higher twist contributions to the integral of $g_1$, the polarised structure function of the nucleon, based on QCD sum rules. By including corrections both to the perturbative contribution and to the low…
We discuss the implications of a "constituent quark" structure of the nucleon for the leading (1/Q^2-) power corrections to the spin structure functions. Our basic assumption is the presence of quark-gluon correlations in the nucleon wave…
We study the effect of parton angular momentum on the twist-four correction to the left-right asymmetry in the electron-deuteron parity-violating deep inelastic scattering (PVDIS). We show that this higher-twist correction is transparent to…
A survey is given on the present knowledge of the polarized parton distribution functions. We give an outlook for further developments desired both on the theoretical as well on the experimental side to complete the understanding of the…
We have compared polarized parton densities determined in the NLO QCD fits to polarized structure functions and spin asymmetries. We consider models of such distributions based on MRST 99 and MRST 2001 fits to non-polarized data. Simple…
The third moment $d_2$ of the twist-3 part of the nucleon spin structure function $g_2$ is generalized to arbitrary momentum transfer $Q^2$ and is evaluated in heavy baryon chiral perturbation theory (HBChPT) up to order…
A new combined NLO QCD analysis of the polarized inclusive and semi-inclusive DIS data is presented. In contrast to previous combined analyses, the 1/Q^2 terms (kinematic - target mass corrections, and dynamic - higher twist corrections) in…
We calculate the spin dependent structure functions g_{1}(x) and g_{2}(x) of the proton and neutron. Our calculation uses the meson cloud model of nucleon structure, which has previously given a good description of the HERMES data on…
We extract parton distribution functions (PDFs) and structure functions from recent experimental data of polarized lepton-DIS on nucleons at next-to-leading order (NLO) Quantum Chromodynamics. We apply the Jacobi polynomial method to the…
We study deep-inelastic scattering from polarized nuclei within a covariant framework. A clear connection is established between relativistic and non-relativistic limits, which enables a rigorous derivation of convolution formulae for the…
We review the nucleon's twist-3 polarized structure functions from the viewpoint of gauge invariant, nonlocal light-cone operators in QCD. We discuss a systematic treatment of the polarized structure functions and the corresponding parton…
I begin with a general discussion about importance of constructing a picture of the nucleon in terms of QCD degrees of freedom, emphasizing the role of spin structure functions. I then give a short overview on the theoretical and…
In this letter we report the direct perturbative QCD evaluation of twist-4 effects in diffractive DIS. They are large and have a strong impact on the $Q^2$ dependence of diffractive structure functions at large $\beta$. Based on the AGK…
Recent progress in the understanding of the nucleon is presented. The unpolarised structure functions are obtained with unprecedented precision from the combined H1 and ZEUS data and are used to extract proton parton distribution functions…